revert auth header changes

Author: prayansh

core/src/main/java/com/segment/analytics/kotlin/core/HTTPClient.kt

@@ -1,6 +1,7 @@
 package com.segment.analytics.kotlin.core
 
 import com.segment.analytics.kotlin.core.Constants.LIBRARY_VERSION
+import com.segment.analytics.kotlin.core.utilities.encodeToBase64
 import java.io.BufferedReader
 import java.io.Closeable
 import java.io.IOException
@@ -12,6 +13,7 @@ import java.net.URL
 import java.util.zip.GZIPOutputStream
 
 class HTTPClient(private val writeKey: String) {
+    internal val authHeader = authorizationHeader(writeKey)
 
     fun settings(cdnHost: String): Connection {
         val connection: HttpURLConnection =
@@ -29,6 +31,7 @@ class HTTPClient(private val writeKey: String) {
         val connection: HttpURLConnection = openConnection("https://$apiHost/b")
         connection.setRequestProperty("Content-Type", "text/plain")
         connection.setRequestProperty("Content-Encoding", "gzip")
+        connection.setRequestProperty("Authorization", authHeader)
         connection.doOutput = true
         connection.setChunkedStreamingMode(0)
         return connection.createPostConnection()
@@ -55,6 +58,11 @@ class HTTPClient(private val writeKey: String) {
         connection.doInput = true
         return connection
     }
+
+    private fun authorizationHeader(writeKey: String): String {
+        val auth = "$writeKey:"
+        return "Basic ${encodeToBase64(auth)}"
+    }
 }
 
 /**

core/src/main/java/com/segment/analytics/kotlin/core/utilities/Base64Utils.kt

@@ -0,0 +1,44 @@
+@file:JvmName("Base64Utils")
+package com.segment.analytics.kotlin.core.utilities
+
+// Encode string to base64
+fun encodeToBase64(str: String) = encodeToBase64(str.toByteArray())
+
+// Encode byte-array to base64, this implementation is not url-safe
+fun encodeToBase64(bytes: ByteArray) = buildString {
+    val wData = ByteArray(3) // working data
+    var i = 0
+    while (i < bytes.size) {
+        val leftover = bytes.size - i
+        val available = if (leftover >= 3) {
+            3
+        } else {
+            leftover
+        }
+        for (j in 0 until available) {
+            wData[j] = bytes[i++]
+        }
+        for (j in 2 downTo available) {
+            wData[j] = 0 // clear out
+        }
+        // Given a 3 byte block (24 bits), encode it to 4 base64 characters
+        val chunk = ((wData[0].toInt() and 0xFF) shl 16) or
+                ((wData[1].toInt() and 0xFF) shl 8) or
+                (wData[2].toInt() and 0xFF)
+
+        // if we have too little characters in this block, we add padding
+        val padCount = (wData.size - available) * 8 / 6
+
+        // encode to base64
+        for (index in 3 downTo padCount) { // 4 base64 characters
+            val char = (chunk shr (6 * index)) and 0x3f // 0b00111111
+            append(char.base64Val())
+        }
+
+        // add padding if needed
+        repeat(padCount) { append("=") }
+    }
+}
+
+private const val ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
+private fun Int.base64Val(): Char = ALPHABET[this]

core/src/test/kotlin/com/segment/analytics/kotlin/core/HTTPClientTests.kt

@@ -57,7 +57,7 @@ class HTTPClientTests {
 
     @Test
     fun `safeGetInputStream properly catches exception`() {
-        val connection = spyk(URL("https://api.segment.io/v1/batch").openConnection() as HttpURLConnection)
+        val connection = spyk(URL("https://api.segment.io/v1/b").openConnection() as HttpURLConnection)
         every { connection.inputStream } throws IOException()
         val errorStream: InputStream? = safeGetInputStream(connection)
         assertEquals(connection.errorStream, errorStream)
@@ -79,4 +79,10 @@ class HTTPClientTests {
             e.message?.let { assertTrue(it.contains("300")) }
         }
     }
+
+    @Test
+    fun `authHeader is correctly computed`() {
+        assertEquals("Basic MXZOZ1Vxd0plQ0htcWdJOVMxc09tOVVIQ3lmWXFiYVE6", httpClient.authHeader)
+    }
+
 }

core/src/test/kotlin/com/segment/analytics/kotlin/core/utilities/Base64UtilsTest.kt

@@ -0,0 +1,20 @@
+package com.segment.analytics.kotlin.core.utilities
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.TestInstance
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class Base64UtilsTest {
+
+    @Test
+    fun testBase64Encoding() {
+        assertEquals(encodeToBase64(""), "")
+        assertEquals(encodeToBase64("f"), "Zg==")
+        assertEquals(encodeToBase64("fo"), "Zm8=")
+        assertEquals(encodeToBase64("foo"), "Zm9v")
+        assertEquals(encodeToBase64("foob"), "Zm9vYg==")
+        assertEquals(encodeToBase64("fooba"), "Zm9vYmE=")
+        assertEquals(encodeToBase64("foobar"), "Zm9vYmFy")
+    }
+}